Climate Prediction Center’s Africa Hazards Outlook September 17 – September 23, 2015
Heavy rains trigger flooding in parts of Nigeria.
Suppressed rainfall continues over parts of southern Ethiopia, South Sudan and Uganda.
1) While a recent increase in August precipitation is expected to lead to more favorable ground moisture, a delayed onset and uneven rainfall distribution observed during the June-September season may negatively impact cropping and pastoral conditions in the region.
2) Despite recent increase in rainfall, the much delayed start to the rainfall season has resulted in drought, which has severely impacted ground conditions and already led to livestock death across parts of north-central and eastern Ethiopia.
3) Well above-average seasonal has led to a saturation of ground conditions in several regions of West Africa. The continuation of heavy rainfall forecast is expected to sustain the risk of flooding across the region for the upcoming outlook period.
4) Well below-average rainfall during August has led to a strengthening of moisture deficits throughout several provinces in southern South Sudan and northern Uganda. Below-average rainfall is expected in the region for the upcoming outlook period.
5) In early September, locally torrential rains resulted in floods, displaced populations, and damages to crops and infrastructure in the Kebbi, Sokoto, Zamfara, and Kano states of northwestern Nigeria. Heavy rains and a dam failure have also led to flooding, affecting thousands of people in the Gombe and Adamawa states of the country.
Average to above-average rainfall is forecast for both regions during the middle of September.
Note: The hazards outlook map on page 1 is based on current weather/climate information and short and medium range weather forecasts (up to 1 week). It assesses their potential impact on crop and pasture conditions. Shaded polygons are added in areas where anomalous conditions have been observed. The boundaries of these polygons are only approximate at this continental scale. This product does not reflect long range seasonal climate forecasts or indicate current or projected food security conditions.
Questions or comments about this product may be directed to Wassila.Thiaw@noaa.gov or 1-301-683-3424.
Average to above-average rains received throughout West Africa during early September.
During early September, well-distributed moderate to locally heavy rainfall was received across much of western Africa. According to satellite data, the highest weekly precipitation accumulations (>100 mm) were registered across local parts of Mali, Senegal, western Niger, and in western and eastern Nigeria. Lesser, but well distributed totals were also received in southern Mauritania, northern Senegal, Guinea. Further south, increased but light rainfall accumulations were received in central portions of Cote d’Ivoire, Ghana and Togo (Figure 1). In Nigeria, significantly heavy rainfall accumulations over a short duration has resulted in flooding, displaced populations, fatalities, and damages to crops and infrastructure in the Gombe, Adamawa, Kebbi, Zamfara, Sokoto, Anambra, and Kano stats in the east and west.
Above-average rains continued further west over parts of southern and central Mali. This region, as well as neighboring regions located in Niger and Burkina Faso have experienced at least 6-8 consecutive weeks of above-average (>120 percent of normal) rainfall according the satellite data (Figure 2). With little opportunity for rainfall relief throughout the monsoon season, these saturated areas are expected to be the most at risk for flooding during early to mid-September. The continuation of above-average rains could trigger additional floods and also damage crops over some overly saturated areas.
For the upcoming outlook period, rainfall forecasts suggest the potential for average to above-average rainfall across many saturated regions in West Africa. The heaviest rainfall accumulations are expected throughout Guinea, central Mali, and Nigeria during the next seven days, sustaining the risk for flooding and other adverse ground impacts.
Dryness worsens in South Sudan, northern Uganda.
During the past week, increased amounts of seasonal precipitation continued across much of northern Ethiopia, Eritrea, and eastern Sudan with totals exceeding >75mm in several local areas in the Tigray and Amhara provinces of Ethiopia. Increased precipitation totals were also received further east into the Afar region, Djibouti, and northern Somalia during the last week, bringing favorable amounts of moisture into some of anomalously dry areas. Although much of the northern portion of the Greater Horn of Africa has been experienced enhanced rainfall since mid-August, suggesting a delayed cessation of seasonal precipitation, many areas further south continue to experience strengthening dryness. Throughout many local parts in southwestern Ethiopia and South Sudan, rainfall has been consistently suppressed since mid-August, leading to a rapid increase in moisture deficits, and increased concerns for available moisture for cropping and pastoral activities. Satellite rainfall anomaly estimates depict considerably low percentiles in the region, with the greatest rainfall deficits concentrated in southern South Sudan and northern Uganda (Figure 3). Here, rainfall has been registered as being the lowest 30- day total over a 30-year period.
During the next seven days, little to no relief is expected for several anomalously dry areas according to precipitation forecasts. Moderate to locally heavy rainfall is forecast for northwestern Ethiopia, with low rainfall totals expected for much of southern Ethiopia, South Sudan and Uganda.
Satellite-Estimated Rainfall (mm) Valid: September 3 – September 12, 2015
Figure 1: NOAA/CPC
Maximum Consecutive Weeks of Above-Average Rainfall Since: June 20, 2015
Figure 2: NOAA/CPC
Satellite-Estimated Rainfall Percentile (%) Valid: August 14 – September 12, 2015
Figure 3: NOAA/CPC
